运用结合双温模型的分子动力学方法, 数值模拟了脉宽为100 fs的超短脉冲激光烧蚀B2结构镍钛形状记忆合金薄膜的作用, 研究了较低能量密度下B2结构镍钛形状记忆合金靶材的相变过程。结果表明, 超快激光与B2结构镍钛形状记忆合金相互作用时, 压力波传播引起了热能的弛豫。脉宽为100 fs, 功率密度为20~35 mJ/cm2的激光与靶材作用时, 烧蚀产生的压力波在其传播过程中诱导靶材发生了相变, 并形成三明治结构。

Incorporating with molecular dynamics method of two-temperature model, the effect of B2 structure Ni-Ti shape memory alloy film ablated by femto-second laser with 100 fs ultra-short pulse width is simulated in number and the phase transition of the target with lower energy density is researched. The results show that thermal energy relaxation is caused by the propagation of pressure wave when ultra-high speed laser interacts with B2 structure Ni-Ti shape memory alloy. The laser with 100 fs pulse width and 20~35 mJ/cm2 power density interacting with the target, the phase change of the target is induced by the pressure wave from ablating process during propagation. And a sandwich structure is formed.